Conventionally, a sliding support device including a slide member (first member) and a counter member (second member) has been known as a sliding support device used for seismically isolated structures. This sliding support device is constructed such that the slide member can slide along the surface of the counter member having a sufficiently large area, and a load can be transmitted from one of the slide member and the counter member to the other. In such a sliding support device, it is important to decrease the friction coefficient on sliding surfaces of the slide member and the counter member as much as possible in view of seismic isolation performance. In order to obtain a friction coefficient equal to or lower than 0.1, it is common to apply a fluid lubricant in the form of gel or liquid such as grease or oil to the sliding surface. However, these fluid lubricants are gradually discharged from the sliding surface in association with sliding, at the time of alternate sliding when the slide member and the counter member repeatedly slide, thereby increasing the friction coefficient on the sliding surface. In order to prevent the lubricant from flowing out and maintain a favorable low friction coefficient state with less maintenance frequency, various support devices as described below have been proposed.
In Patent Documents 1 and 2, there are proposed support devices in which a slide member is made of self-lubricating resin and concave machining is applied to the surface thereof to fill a lubricant therein, and a counter member is made of a leveling material, the surface of which is formed smoothly, so that lubricating ability on the sliding surfaces thereof is maintained.
In the support device described in Patent Document 1, a concave portion is provided in a solid slide member having a low friction coefficient, a gel lubricant is sealed in the concave portion, and the gel lubricant is also applied to around the concave portion. On the other hand, the counter member is made from a stainless steel plate, or a surface of a resin plate applied with tetrafluoroethylene is formed as a smooth surface.
In the support device described in Patent Document 2, a concave portion is formed which communicates with a surface of a slide member made from tetrafluoroethylene resin and does not have an open end at an outer edge thereof, and a lubricant made of fluorine grease is applied thereto. On the other hand, the counter member is made using a smooth plate having a smooth surface. Surface roughness of the smooth plate is set such that a maximum height Rz defined by JIS B0601-2001 (ISO 4287) is from 0.05 to 0.50 μm (preferably, from 0.10 to 0.20 μm).
In the support device described in Patent Document 3, a slide member is made of synthetic resin having a relatively high strength, and concave machining is applied to the surface thereof to fill a lubricant therein. On the other hand, the counter member is formed of a plate with a thin synthetic resin surface having a surface elastic modulus (Young's modulus) equal to or lower than that of the slide member. Thus, in Patent Document 3, a support device is proposed in which the strength of the counter member is ensured.
In the support device described in Patent Document 3, the slide member is made of synthetic resin (polyacetal, polyamide, polyphenylene ether, phenol, glass fiber-containing polycarbonate, and the like) having a compressive strength of from 50 to 120 MPa, and the counter member includes a self-lubricating synthetic resin film made of polyamideimide resin or epoxy resin containing tetrafluoroethylene. The synthetic resin film of the counter member has a film thickness of 100 μm or less (preferably, from 20 to 40 μm), so that a friction coefficient (μ) as low as 0.02 to 0.04 can be obtained on sliding surfaces of the slide member and the counter member.
In Patent Document 4, there is proposed a support device in which a slide member is made of tetrafluoroethylene resin (self-lubricating resin) having holes produced using a special method and impregnated with a fluid lubricant, and the surface of a counter member is coated with resin formed by the same method. Thus, in Patent Document 4, a support device is proposed that prevents a lubricant from flowing out to thereby maintain the low friction coefficient state.
The support device described in Patent Document 4 is formed of a porous compact with a plurality of voids in which at least one of the slide member and the counter member is formed of a composition containing aromatic polyester which consists primarily of tetrafluoroethylene resin. In the support device described in Patent Document 4, outflow of the lubricant is prevented by impregnating a polysiloxane (silicone) lubricant in the voids.
In Patent Documents 5 and 6, there is proposed a support device in which a slide member is made of a self-lubricating resin, and a sliding surface of a counter member is coated with a resin film made by chemical bonding of fluorine-containing polymer and silicone oil, thereby preventing the lubricant from flowing out.
In the support device described in Patent Document 5, the sliding surface of the slide member is made of a self-lubricating synthetic resin. On the other hand, on the sliding surface of the counter member, there is formed a deposited film of a composition solidifying material comprising epoxy resin and reactive silicone oil with an epoxy equivalent weight equal to or less than 1000 having an epoxy group in a side chain. In the composition solidifying material, reactive silicone oil forms a three-dimensional reticular structure by calcination treatment at 180° C., thereby preventing silicone oil from flowing out.
In the support device described in Patent Document 6, the sliding surface of the slide member is formed of a resin consisting primarily of tetrafluoroethylene resin, and the counter member is made of a metal plate having an overlying film on the surface thereof. The overlying film is formed singly or as a compound, from a fluorine-containing polymer having a functional group at the end, or an organosiloxane, with a film thickness thereof being about 0.01 to 5 μm.